How to Sign a PDF on iPhone or iPad

A phone is the best device for signing, because you can actually write on the screen. A finger beats a mouse comfortably, and an Apple Pencil produces a signature indistinguishable from ink.

Using Markup, built into iOS

1. 1Open the PDF in Files, Mail or Safari.
2. 2Tap the Markup icon — the pen tip in a circle.
3. 3Tap +, then Signature.
4. 4Draw your signature, or pick one you saved earlier.
5. 5Drag and resize it into position, then tap Done.
6. 6Share the signed file from the share sheet.

iOS stores your saved signature for reuse, so after the first time signing takes about ten seconds.

Using a browser tool instead

Markup is quick but rough: placement is by eye, sizing is a pinch, and there is no preview of the finished page other than what you are looking at. A browser-based signing tool gives you a proper preview of the signed document and a choice between drawing, typing and uploading a signature — and it works the same on the phone as on a laptop.

Both keep the document on the device. Neither uploads your contract, which for signed documents is the property that matters.

Signing well on a small screen

• Turn the phone to landscape — a wider canvas produces a better signature.
• Zoom into the signature area before positioning, so you can see the line you are signing on.
• Draw larger than needed; it scales down cleanly and the wobble disappears.
• Use an Apple Pencil if you have one. The difference is substantial.
• Check the whole page afterwards, not just the signature.

Sending it back

Reply to the original email and attach the signed PDF rather than starting a new thread — it keeps the record together. Say in the message that the signed copy is attached and note the date. If it is going to a portal, check the size limit first; a signed document is rarely large, but a scanned one can be.